libstdc++: Fix compilation of <ranges> with Clang (PR 93818)

libstdc++: Fix compilation of <ranges> with Clang (PR 93818)

	PR libstdc++/93818
	* include/std/ranges (_RangeAdaptor): Add deduction guide.
	(filter_view::_Iterator): Add alias _Vp_iter and use in place of
	iterator_t<_Vp>.
	(filter_view::_Iterator::_S_iter_cat()): Add 'typename'.
	(transform_view::_Iterator): Add alias _Base_iter and use in place of
	iterator_t<_Base>.
	(transform_view::_Iterator::_S_iter_cat()): Add 'typename'.
	(join_view::_Iterator): Add _Outer_iter and _Inner_iter aliases.
	(join_view::_Iterator::_S_iter_cat()): Add 'typename'.
	(split_view::_InnerIter::_S_iter_cat()): Likewise.